Motility of cancer cells plays a critical role in tumor metastasis, and as such is a target for intervention. The motility
of malignant Calu-1 human lung epithelial carcinoma cells is upregulated when placed on a human umbilical vein endothelial
cell monolayer, while that of non-malignant L132 human lung epithelial cells is not. To dissect the factor(s) causing such
differential behaviors, the motile responses of both cell lines to endothelial cell factors—secreted to the media, on the
endothelial cell surface, and secreted to the extracellular matrix—and to individual extracellular matrix proteins were compared.
Cell motility was quantified by tracking the cell movement on a surface with time-lapse video microscopy, which was analyzed
with the persistent random walk model of motility. None of the factors tested had a remarkable effect on L132 cell motility,
but the Calu-1 cell motility was significantly upregulated by endothelial cell extracellular matrix and by laminin, fibronectin,
collagen I and collagen VI individually. Flow cytometry analysis revealed significantly higher expression levels of integrin
subunits
β1,
α2,
α3, and
α6, which are known receptors for these extracellular matrix proteins, on the Calu-1 than L132 cells, implicating a role of
these integrins in the observed motile behaviors of these cell lines.
Keywords Tumor cell motility - Persistent random walk - Extracellular matrix - Integrin